phase linear 400

[gene french]

no sir....once i was secure in no meltdown....i switched to shore power and set both channels
i dont know how to set the bias....i did not see that in the service manual...can you advise me how...
man, those are some heavy duty caps you have in your kit....i unplugged the amp....it kept playing for around 6 seconds...
thought i was having a come to jesus moment...
i am pretty sure that i will have to recalibrate after i recap anyway...i mainly did that to clean and spin around the pots...as advised...
and btw...no more scratching.....sounds nice...
i see two more pots on the driver board...must be the bias adjustment....
the 400 is off line until i get the protection kit in and finish the recap work...but, i will only do one thing at a time and play in between....
dont want more than one problem at a time...lol
waiting for the cap kit...and your light upgrade too...
thanks for your advice and comments...
this is a nice forum...

 

[J!m]

Good idea to test after each change to make sure you don’t do more harm than good.

Unkess you’re someone like Joe or Perry,

 

[Vintage 700b]

well, just installed the white oak cap replacement..
then took advice i received and cleaned the adjustment pot....readjusted...less yhan 1mv...i am happy...it plays just fine...waiting on more parts to arrive!!!
still using dim bulb and throw away speakers...lol
not that i am afraid....lol
peace

Looking good Gene, that 400 is CLEAN inside

 

[gene french]

in the service manual that i have....from hifi engine dated 1976 which includes my serial number...
i definitely have a 400c board...
the r8 was easily adjusted as directed in the manual...
i went back and found the bias adjustment in the docs....
but....
a. the manual refers to reading across r38....my unit does not have an r38...
b. the manual refers to tweaking r20....my unit has an r14....
can anyone shed some light on this....my "flashlight" is dim...
thanks...
gene french

 

[gene french]

Looking good Gene, that 400 is CLEAN inside

thank you so much!!!!
maybe i lucked out....

 

[gene french]

You’re not playing the amp with the dim bulb are you? Final bias should be set with no DBT also.

no sir...once running without imploding after a change i made....i switched to normal current....
and set the offset...

 

[Gepetto]

R38 is a 10 ohm resistor on the back wall assembly...

 

[gene french]

thank you...
i will be adjusting r14??
or is r20 somewhere else.
i appreciate yoir time

 

[gene french]

just finished up the wattsabundant speaker protect kit......
looks nice....it is playing now....
now that r38 is removed i still dont know how to set the bias...
can anyone help me with that...????

 

[Gepetto]

just finished up the wattsabundant speaker protect kit......
looks nice....it is playing now....
now that r38 is removed i still dont know how to set the bias...
can anyone help me with that...????

Yes I will send you a picture in about an hour using the photo on the left side that you just posted

 

[Gepetto]

Yes I will send you a picture in about an hour using the photo on the left side that you just posted

In your left hand photo. Look at the second column of sockets to the left of the DCP board you just installed. The small 10 ohm resistor right below the 0.22 ohm resistor at the top. Measure across this with your DVM. Set for 0.35v. Do the same on the left channel

 

[gene french]

thank you....maybe this week the light bar will show up...

 

[Gepetto]

thank you....maybe this week the light bar will show up...

Markup is now in the prior post

 

[gene french]

i got it...one side was 300mv and the other side 280mv...but, i had marked them and sprayed then exercised the pots, before returniing it to the marks...
was not a problem to set...i would have never figured that one out from the manual....thanks for taking the time to advise me...
unit is looking better and better every day!!!
should i build up a 700....didnt you say the 700b is the one to have???
again...thank you

 

[Gepetto]

i got it...one side was 300mv and the other side 280mv...but, i had marked them and sprayed then exercised the pots, before returniing it to the marks...
was not a problem to set...i would have never figured that one out from the manual....thanks for taking the time to advise me...
unit is looking better and better every day!!!
should i build up a 700....didnt you say the 700b is the one to have???
again...thank you

700B or 700 Series 2 are the ones to get depending on if you prefer the analog or LED style meters. The amps are basically the same.

 

[gene french]

thank you so much....

 

[gene french]

good morning....
still waiting on the cap kit...which is stuck in customs for physical inspection....whatever that means...
light bar is progressing through the process....with a little luck maybe both will be here this week!!!
i am still getting a slight scratching on the left channel on cold power up....it does not do it any other time...
ie. after sitting overnight then first power up....lasts 10 to 15 seconds....
a little perplexed....when i set the offset and bias...i sprayed and exercised the pots....several times...
was easily set .... not jerky or all over the place...
comments??
please, and thank you!!!

700B or 700 Series 2 are the ones to get depending on if you prefer the analog or LED style meters. The amps are basically the same.

i think i will be happier with the analog...my 200 does not impress as much as the analog meters on the 400...
700b series 1...
thanks again

 

[AngrySailor]

good morning....
still waiting on the cap kit...which is stuck in customs for physical inspection....whatever that means...
light bar is progressing through the process....with a little luck maybe both will be here this week!!!
i am still getting a slight scratching on the left channel on cold power up....it does not do it any other time...
ie. after sitting overnight then first power up....lasts 10 to 15 seconds....
a little perplexed....when i set the offset and bias...i sprayed and exercised the pots....several times...
was easily set .... not jerky or all over the place...
comments??
please, and thank you!!!

i think i will be happier with the analog...my 200 does not impress as much as the analog meters on the 400...
700b series 1...
thanks again

“Physical inspection” they’re drilling holes through your capacitors looking for cocaine!

here’s my 700 series 1, with the asymmetric meters. It’s got the white oak driver board, caps and Don’s DCP but running factory quasi-comp back planes for now as the white oak back planes don’t fit the 700/1 chassis. It’s sounds great with those upgrades but I can’t wait to get my full WOPL 400/1 finished to get the whole experience! Basically I wouldn’t shy away from the 700/1 if you like the looks. They can be upgraded fully now with the new chassis available. I was sent a full-comp 700 pro back wall by another member here which I may install in mine should I nuke it...

 

[gene french]

“Physical inspection” they’re drilling holes through your capacitors looking for cocaine!

here’s my 700 series 1, with the asymmetric meters. It’s got the white oak driver board, caps and Don’s DCP but running factory quasi-comp back planes for now as the white oak back planes don’t fit the 700/1 chassis. It’s sounds great with those upgrades but I can’t wait to get my full WOPL 400/1 finished to get the whole experience! Basically I wouldn’t shy away from the 700/1 if you like the looks. They can be upgraded fully now with the new chassis available. I was sent a full-comp 700 pro back wall by another member here which I may install in mine should I nuke it...

nice unit....i bet it sounds wonderful....
i am gonna keep my eyes open for one....if i can find a good deal...
remember i have to pay 2 freights and an import tax....it costs a lot more to get it in my hand...
lol....
price of doing business...
thanks for sharing...i enjoy

 

[gene french]

what a nice led upgrade joe....nice quality...
it is the perfect amount of light for me...not too bright...not too dim...
these pics are in the daylight with my den with 5 nice sized picture windows....plenty of natural light....
the meters show up nicely!!!
the cap kit came in today also....
maybe by tomorrow, i can wrap this up....for now...
lol
thanks everybody!!!!